Six Big Losses of OEE

The Six Big Losses are utmost important to know as they are nearly generic in all the applications universally for manufacturing and they are the most common causes of productivity loss. This losses are nothing but the broken parts of the OEE components -Availability Loss, Performance Loss and Quality Loss. They can provide a great starting framework to ponder over.

Unplanned Stops
It is an Availability Loss. Unplanned stoppages account for any stipulated amount of time when an equipment is scheduled for production but isn’t running due to some sort of failure. Some common failure examples include equipment failure, breakdowns, unplanned maintenance, etc.

Setup and Adjustments
This loss is usually addressed through setup time reduction programs. This an availability loss which can be termed as planned stoppage. This happens when a machine is scheduled for production but is not running because of tools adjustment or changeover or material shortage.

Small StopsSmall stops happen when a running equipment stops for a very short period of time (a minute or two) which is resolved and restarted by the concerned operator. This is a performance loss and also known as Idling and Minor stop. Some common reason of such failure are misfeeds, material jams, quick cleaning, blocked sensors, etc

Slow Cycles
This issue accounts for the event when an equipment runs slower that its expected or the ideal cycle time. Slow Cycles is a Performance Loss. Anything that prevents the machine from running at its nameplate capacity can be put under this category.

Production Rejects
It raises attention on the rejection of products due to defective parts produced during stable (or steady) production state. Production (or process) defects are quality loss since OEE measures quality from the First Pass Yield perspective.

Reduced Yield Startup Rejects
It consists of the defective parts that are produced by startup until stable (or steady) production is reached. It includes both rework able and scrapped parts as per OEE quality measures. Also known as reduced yield, is a Quality Loss. Some examples are incorrect settings, suboptimal changeovers, wrong warm-up cycles, etc